package com.fcmeditech.AsianSexyGirls.File;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.Stack;
import java.util.WeakHashMap;

import com.fcmeditech.AsianSexyGirls.R;


import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;

public class ListViewImageLoader {
	
	    MemoryCache memoryCache=new MemoryCache();
	    FileCache fileCache; 
	    private Context mContext;
	    
	    private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
	    
	    public ListViewImageLoader(Context context){
	        //Make the background thead low priority. This way it will not affect the UI performance
	        photoLoaderThread.setPriority(Thread.NORM_PRIORITY-1);
	        mContext = context;
	        fileCache=new FileCache(context);
	    }
	    
	    final int stub_id=R.drawable.stub;// Image Default
	    
	    public void DisplayImage(String url, Activity activity, ImageView imageView)
	    {
	        imageViews.put(imageView, url);
	        Bitmap bitmap=memoryCache.get(url);
	        if(bitmap!=null){
	            imageView.setImageBitmap(bitmap);}//If true-->set null;false-->set bitmap
	        else
	        {
	            queuePhoto(url, activity, imageView);
	            imageView.setImageResource(stub_id);
	        }    
	    }
	        
	    public Bitmap GetImage(String url, Activity activity, ImageView imageView)
	    {
	        imageViews.put(imageView, url);
	        Bitmap bitmap=memoryCache.get(url);
	        if(bitmap!=null)
	        {
	            imageView.setImageBitmap(bitmap);
	        	return bitmap;
	        }
	        else
	        {
	            queuePhoto(url, activity, imageView);
//	            imageView.setImageResource(stub_id);
	            return BitmapFactory.decodeResource(mContext.getResources(), R.drawable.stub);          
	        }    
	    }
	    
	    private void queuePhoto(String url, Activity activity, ImageView imageView)
	    {
	        //This ImageView may be used for other images before. So there may be some old tasks in the queue. We need to discard them. 
	        photosQueue.Clean(imageView);
	        PhotoToLoad p=new PhotoToLoad(url, imageView);
	        synchronized(photosQueue.photosToLoad){
	            photosQueue.photosToLoad.push(p);
	            photosQueue.photosToLoad.notifyAll();
	        }
	        
	        //start thread if it's not started yet
	        if(photoLoaderThread.getState()==Thread.State.NEW)
	            photoLoaderThread.start();
	    }
	    
	    private Bitmap getBitmap(String url) 
	    {
	        File f=fileCache.getFile(url);
	        
	        //from SD cache
	        Bitmap b = decodeFile(f);
	        if(b!=null)
	            return b;
	        
	        //from web
	        try {
	            Bitmap bitmap=null;
	            URL imageUrl = new URL(url);
	            HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection();
	            conn.setConnectTimeout(30000);
	            conn.setReadTimeout(30000);
	            InputStream is=conn.getInputStream();
	            OutputStream os = new FileOutputStream(f);
	            Utils.CopyStream(is, os);
	            
	            os.flush();
	            os.close();
	            is.close();
	            
	            bitmap = decodeFile(f);
	            return bitmap;
	        } catch (Exception ex){
	           ex.printStackTrace();
	           return null;
	        }
	    }

	    //decodes image and scales it to reduce memory consumption
	    private Bitmap decodeFile(File f){
	        try {
	            //decode image size
	            BitmapFactory.Options o = new BitmapFactory.Options();
	            o.inJustDecodeBounds = true;
	            BitmapFactory.decodeStream(new FileInputStream(f),null,o);
	            // No scale
	            //Find the correct scale value. It should be the power of 2.
	            final int REQUIRED_SIZE=70;
	            int width_tmp=o.outWidth, height_tmp=o.outHeight;
	            int scale=1;
	            while(true){
	                if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
	                    break;
	                width_tmp/=2;
	                height_tmp/=2;
	                scale*=2;
	            }
	            
	            //decode with inSampleSize
	            BitmapFactory.Options o2 = new BitmapFactory.Options();
	            o2.inSampleSize=scale;
	            return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
	        } catch (FileNotFoundException e) {}
	        return null;
	    }
	    
	    //Task for the queue
	    private class PhotoToLoad
	    {
	        public String url;
	        public ImageView imageView;
	        public PhotoToLoad(String u, ImageView i){
	            url=u; 
	            imageView=i;
	        }
	    }
	    
	    PhotosQueue photosQueue=new PhotosQueue();
	    
	    public void stopThread()
	    {
	        photoLoaderThread.interrupt();
	    }
	    
	    //stores list of photos to download
	    class PhotosQueue
	    {
	        private Stack<PhotoToLoad> photosToLoad=new Stack<PhotoToLoad>();
	        
	        //removes all instances of this ImageView
	        public void Clean(ImageView image)
	        {
	            for(int j=0 ;j<photosToLoad.size();){
	                if(photosToLoad.get(j).imageView==image)
	                    photosToLoad.remove(j);
	                else
	                    ++j;
	            }
	        }
	    }
	    
	    class PhotosLoader extends Thread {
	        public void run() {
	            try {
	                while(true)
	                {
	                    //thread waits until there are any images to load in the queue
	                    if(photosQueue.photosToLoad.size()==0)
	                        synchronized(photosQueue.photosToLoad){
	                            photosQueue.photosToLoad.wait();
	                        }
	                    if(photosQueue.photosToLoad.size()!=0)
	                    {
	                        PhotoToLoad photoToLoad;
	                        synchronized(photosQueue.photosToLoad){
	                            photoToLoad=photosQueue.photosToLoad.pop();
	                        }
	                        Bitmap bmp=getBitmap(photoToLoad.url);
	                        memoryCache.put(photoToLoad.url, bmp);
	                        String tag=imageViews.get(photoToLoad.imageView);
	                        if(tag!=null && tag.equals(photoToLoad.url)){
	                            BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad.imageView);
	                            Activity a=(Activity)photoToLoad.imageView.getContext();
	                            a.runOnUiThread(bd);
	                        }
	                    }
	                    if(Thread.interrupted())
	                        break;
	                }
	            } catch (InterruptedException e) {
	                //allow thread to exit
	            }
	        }
	    }
	    
	    PhotosLoader photoLoaderThread=new PhotosLoader();
	    
	    //Used to display bitmap in the UI thread
	    class BitmapDisplayer implements Runnable
	    {
	        Bitmap bitmap;
	        ImageView imageView;
	        public BitmapDisplayer(Bitmap b, ImageView i){bitmap=b;imageView=i;}
	        public void run()
	        {
	            if(bitmap!=null)
	                imageView.setImageBitmap(bitmap);
	            else
	                imageView.setImageResource(stub_id);
	        }
	    }

	    public void clearCache() {
	        memoryCache.clear();
	        fileCache.clear();
	    }

	}


